1. Field of Invention
The present disclosure pertains to the field of dunnage bags. More specifically, the present specification discloses improvements to inflation valve assemblies for dunnage bags and related methods of use.
2. Background of the Invention
Dunnage bags are airbags that are used in the cargo shipment or transportation industry to secure or brace cargo within the holds of a conveyance (e.g., a railroad car, shipping containers, boats or ships, truck trailers, and the like). In most cases, dunnage bags comprise an inflatable bladder with a valve assembly, wherein naturally compressed air, pressurized air, or other gasses may be, via the valve assembly, either (1) conducted to within the bladder for inflation of a deflated bag, (2) retained within the bladder of an inflated bag, or (3) exhausted from the bladder for deflating an inflated bag. In use, deflated dunnage bags are inflated within voids located between either (a) adjacent cargo loads or (b) cargo loads and the walls of a cargo hold whereby cargo loads are secured against undesirable movements during transport by the inflated bags.
In view of the forgoing, dunnage bag valve assemblies are frequently configured to electively: conduct air or other gasses into the bladder; retain the air or gasses within the bladder; and exhaust the air or other gasses from the bladder. Until this disclosure, such configuration has comprised: a tubular valve body defining a hollow space therewith and an annular flange portion, wherein the tubular valve body is adapted for insertion through an aperture in the bladder so that a free distal end of the body projects outward from the bladder to provide fluid communication between the inside and outside of the bladder, and wherein the flange portion is coupled to the rim of the aperture in the bladder in an air-tight manner; and a flapper member pivotally disposed within or adjacent to the hollow space, wherein the flapper member is adapted to close the hollow space when pivoted to a first position and open the hollow space when pivoted to a second position toward the inside of the bladder. See, e.g., FIGS. 2 through 7 of U.S. Pat. No. 6,823,905 (issued Nov. 30, 2004). While capable of being implemented in a dunnage bag, such valve assemblies have not been entirely satisfactory for their intended purposes.
One unsatisfactory aspect of such valve assemblies is that the flapper member of the valve assembly becomes biased to a closed position after partial inflation of the bladder due to back pressure caused by gasses in the bladder. Said bias is unsatisfactory for deflating a bladder in many instances because deflation cannot occur without propping the flapper member with a foreign object. Accordingly, there is a need for dunnage bag air assemblies that can be used to deflate dunnage bags without fighting back pressure and without using a foreign object to prop a flapper member.